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1.
Biomacromolecules ; 23(10): 4401-4411, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-36173091

RESUMO

The ongoing rise in diabetes incidence necessitates improved therapeutic strategies to enable precise blood glucose control with convenient device form factors. Microneedle patches are one such device platform capable of achieving therapeutic delivery through the skin. In recent years, polymeric microneedle arrays have been reported using methods of in situ polymerization and covalent crosslinking in microneedle molds. In spite of promising results, in situ polymerization carries a risk of exposure to toxic unreacted precursors remaining in the device. Here, a polymeric microneedle patch is demonstrated that uses dynamic-covalent phenylboronic acid (PBA)-diol bonds in a dual role affording both network crosslinking and glucose sensing. By this approach, a pre-synthesized and purified polymer bearing pendant PBA motifs is combined with a multivalent diol crosslinker to prepare dynamic-covalent hydrogel networks. The ability of these dynamic hydrogels to shear-thin and self-heal enables their loading to a microneedle mold by centrifugation. Subsequent drying then yields a patch of uniformly shaped microneedles with the requisite mechanical properties to penetrate skin. Insulin release from these materials is accelerated in the presence of glucose. Moreover, short-term blood glucose control in a diabetic rat model following application of the device to the skin confirms insulin activity and bioavailability. Accordingly, dynamic-covalent crosslinking facilitates a route for fabricating microneedle arrays circumventing the toxicity concerns of in situ polymerization, offering a convenient device form factor for therapeutic insulin delivery.


Assuntos
Diabetes Mellitus , Insulina , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos/métodos , Glucose , Hidrogéis , Insulina/química , Agulhas , Polímeros/química , Ratos
2.
J Am Chem Soc ; 138(46): 15177-15188, 2016 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-27762552

RESUMO

A metastable, polymorphic hexameric crystal structure of lithium pinacolone enolate (LiOPin) is reported along with three preparation methods. NMR-based structural characterization implies that the lithium pinacolate hexamer deaggregates to a tetramer in toluene but retains mainly the hexameric structure in nonaromatic hydrocarbon solvents such as cyclohexane. Moreover, the presence of a small amount of lithium aldolate (LiOA) dramatically influences the aggregation state of LiOPin by forming a mixed aggregate with a 3:1 ratio (LiOPin3·LiOA).

3.
Cancer ; 122(22): 3564-3575, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27433786

RESUMO

BACKGROUND: Prostate-specific antigen (PSA) screening may reduce death due to prostate cancer but leads to the overdiagnosis of many cases of indolent cancer. Targeted use of PSA screening may reduce overdiagnosis. Multimarker genomic testing shows promise for risk assessment and could be used to target PSA screening. METHODS: To test whether counseling based on the family history (FH) and counseling based on a genetic risk score (GRS) plus FH would differentially affect subsequent PSA screening at 3 months (primary outcome), a randomized trial of FH versus GRS plus FH was conducted with 700 whites aged 40 to 49 years without prior PSA screening. Secondary outcomes included anxiety, recall, physician discussion at 3 months, and PSA screening at 3 years. Pictographs versus numeric presentations of genetic risk were also evaluated. RESULTS: At 3 months, no significant differences were observed in the rates of PSA screening between the FH arm (2.1%) and the GRS-FH arm (4.5% with GRS-FH vs. 2.1% with FH: χ2 = 3.13, P = .077); however, PSA screening rates at 3 months significantly increased with given risk in the GRS-FH arm (P = .013). Similar results were observed for discussions with physicians at 3 months and PSA screening at 3 years. Average anxiety levels decreased after the individual cancer risk was provided (P = .0007), with no differences between groups. Visual presentation by pictographs did not significantly alter comprehension or anxiety. CONCLUSIONS: This is likely the first randomized trial of multimarker genomic testing to report genomic targeting of cancer screening. This study found little evidence of concern about excess anxiety or overuse/underuse of PSA screening when multimarker genetic risks were provided to patients. Cancer 2016;122:3564-3575. © 2016 American Cancer Society.

5.
Genet Test Mol Biomarkers ; 16(3): 187-92, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21992462

RESUMO

Fragile X syndrome (FXS) is caused by the absence of a functional fragile X mental retardation protein (FMRP). In most cases, the molecular mutation is an expansion and consequent methylation of the CGG trinucleotide repeat in the 5' end of the FMR1 gene. Polymerase chain reaction (PCR)-based assays that overcome the limitations of amplifying >100-150 CGG repeats have been designed. One such product, Human FMR1 PCR Reagents, can detect expanded mutation alleles without determining methylation status. We used this assay to amplify 70 clinical samples previously tested in three clinical laboratories, including 28 full mutation alleles, 17 premutation alleles, 6 gray zone alleles, and 21 normal samples (51 normal alleles including 5 homozygous females). The results were concordant with previously reported results. All full and premutation alleles were identifiable: repeat sizes are not assigned when the CGG repeat number is >200 and all full and premutation alleles were scored in the same category using this assay. All normal and gray zone alleles were within 0-1 repeat of their previously reported allele sizes. This method identified a mosaic premutation/full mutation pattern in 12/21 samples previously identified as full mutation only and in 5/7 samples previously reported as mosaic premutation/full mutation. These results demonstrate that this assay provides comparable results to the combination of PCR/Southern blot methodologies. Additional issues such as technologist time, reagent costs, turnaround times, and sample requirements are comparable to the PCR/Southern blotting assays currently utilized; however, methylation status cannot be determined using this assay. It is likely that PCR-only based assays will eventually replace previous methods for FXS and that Southern blotting or another methylation assay will only be utilized when determination of methylation status is necessary. This type of assay may also be utilized for other nucleotide expansion disorders.


Assuntos
Técnicas de Laboratório Clínico/métodos , Proteína do X Frágil da Deficiência Intelectual/genética , Indicadores e Reagentes , Reação em Cadeia da Polimerase/métodos , Alelos , Southern Blotting , Metilação de DNA , Eletroforese Capilar/métodos , Feminino , Síndrome do Cromossomo X Frágil/diagnóstico , Síndrome do Cromossomo X Frágil/genética , Humanos , Masculino , Mutação , Kit de Reagentes para Diagnóstico , Expansão das Repetições de Trinucleotídeos/genética
6.
Mol Cancer Ther ; 9(8): 2423-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20682649

RESUMO

Prior studies suggest that tumor cell lines harboring RAS mutations display remarkable sensitivity to gemcitabine and etoposide. In a phase II clinical trial of patients with locally advanced or metastatic pancreatic cancer, we evaluated the response rate to a combination of these drugs. Forty chemo-naïve patients with nonresectable and histologically confirmed pancreatic cancer were accrued. Patients received gemcitabine 1,000 mg/m(2) (days 1 and 8) and etoposide 80 mg/m(2) (days 8, 9, and 10; 21-day cycle). The primary end point was radiological response rate. Secondary objectives were determination of overall survival, response duration (time to progression), quality of life, toxicity, and CA 19-9 biomarker response. In 35 evaluable patients, 10 exhibited a radiological partial response and 12 had stable disease in response to treatment. Twenty patients exhibited a >20% decrease in CA 19-9 biomarker levels. Median overall survival was 6.7 months for all patients (40) and 7.2 months for evaluable patients (35). Notably, four patients survived for longer than 1 year, with two patients surviving for more than 2 years. Median time to progression for evaluable patients was 3.1 months. The median overall survival for locally advanced patients was 8.8 months and 6.75 months for metastatic patients. One-year survival was 10% for all patients and 11.4% for evaluable patients. Quality of life improved in 12 patients and remained stable in 3 of the evaluable patients. The primary dose-limiting toxicities were hematologic toxicity and fatigue. These results show that the gemcitabine and etoposide combination is generally well-tolerated and exhibits a response rate similar to other published studies.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Desoxicitidina/análogos & derivados , Etoposídeo/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Adulto , Idoso , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Etoposídeo/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/tratamento farmacológico , Estadiamento de Neoplasias , Análise de Sobrevida , Gencitabina
7.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 7): o1678, 2010 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-21587903

RESUMO

The title compound, C(18)H(19)NO(4), was prepared as an indole derivative with possible anti-mitotic properties. The planes of the indole and trimethoxy-phenyl rings make a dihedral angle of 45.35 (5)° with one another. In the crystal, mol-ecules related by a twofold screw axis exhibit arene C-H⋯arene-π inter-actions which are 3.035 (1) Šin length.

8.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 10): o2353, 2009 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-21577822

RESUMO

The title compound, C(12)H(13)NO(4), was prepared as a precursor to an indole derivative with possible anti-mitotic properties. The mol-ecule is very nearly planar; the maximum deviation of any non-H atom from the mean plane of the indole ring is 0.120 (3) Šfor each of two meth-oxy C atoms. The pairs of mol-ecules related by the inversion centre at (0,0,) are connected by two symmetry-equivalent N-H⋯O hydrogen bonds, while the pairs of mol-ecules related by the inversion centre at (0,0,0) exhibit a π-stacking inter-action of the indole rings, with an inter-planar separation of 3.39 (3) Å.

9.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 11): m1421, 2009 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-21578157

RESUMO

The title compound, [Zn(C(6)H(5)S)(2)(C(18)H(12)N(2))], was prepared as a model for future complexes that will be incorporated into light-harvesting arrays. The Zn(II) atom lies on a twofold rotation axis and the ligands are arranged tetra-hedrally around this atom. The benzene-thiol-ate ligand and the biquinoline ligand are nearly perpendicular to one another, making a dihedral angle of 84.09 (5)°. The biquinoline ligand is nearly planar, with a maximum deviation of 0.055 (3) Šfrom the mean plane of the ring system. In the crystal, the mol-ecules pack in a manner such that the biquinoline ligands are parallel to one another, with a π-π inter-action [interplanar distance = 3.38 (1) Å] with the neighboring biquinoline ligand.

10.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 1): o132, 2009 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-21580023

RESUMO

The title compound, C(34)H(28)Si, was prepared as an inter-nal standard for diffusion-ordered NMR spectroscopy. The four ligands are arranged tetra-hedrally around the Si atom. The two naphthalene systems are nearly perpendicular, making an angle of 86.42 (4)° with one another. A naphthalene system and a phenyl ring are also nearly perpendicular, making an angle of 86.18 (6)° with one another. In the crystal, the mol-ecules pack in columns parallel to the a axis, and exhibit arene C-H⋯π(arene) inter-actions both within and between columns.

11.
Am J Surg ; 191(3): 410-2, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16490557

RESUMO

BACKGROUND: Local excision has been accepted therapy for T1 rectal cancers. A recent study demonstrated that primary tumors with deeper submucosal invasion were associated with a higher rate of lymph node metastases than those with shallow invasion. Our aim was to determine the effect of the depth of submucosal penetration on recurrence and mortality rates following transrectal excision of T1 tumors. METHODS: This was a 34-year retrospective review of patients who had transrectal excision with clear margins for T1 rectal cancer. Tumors were stratified into submucosal (SM) levels, and recurrence and mortality rates were determined. RESULTS: Of 101 patients with T1 rectal cancer undergoing local excision, 31 had a full-thickness transrectal excision. Eight (26%) of the 31 patients developed a local recurrence, 2 of whom had both a local and distant recurrence. Four patients (13%) died from metastatic rectal cancer. CONCLUSIONS: The recurrence rate for transrectal excision of T1 rectal cancer is high. It may be beneficial for patients with early rectal cancer to have postoperative chemoradiation therapy or a more radical surgical procedure.


Assuntos
Carcinoma/patologia , Carcinoma/cirurgia , Mucosa Intestinal/patologia , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Idoso , Carcinoma/mortalidade , Feminino , Humanos , Modelos Logísticos , Metástase Linfática , Masculino , Invasividade Neoplásica , Recidiva Local de Neoplasia/epidemiologia , Neoplasias Retais/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
12.
J Digit Imaging ; 18(3): 203-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15924273

RESUMO

The PACS implementation process is complicated requiring a tremendous amount of time, resources, and planning. The Department of Defense (DOD) has significant experience in developing and refining PACS acceptance testing (AT) protocols that assure contract compliance, clinical safety, and functionality. The DOD's AT experience under the initial Medical Diagnostic Imaging Support System contract led to the current Digital Imaging Network-Picture Archiving and Communications Systems (DIN-PACS) contract AT protocol. To identify the most common system and component deficiencies under the current DIN-PACS AT protocol, 14 tri-service sites were evaluated during 1998-2000. Sixteen system deficiency citations with 154 separate types of limitations were noted with problems involving the workstation, interfaces, and the Radiology Information System comprising more than 50% of the citations. Larger PACS deployments were associated with a higher number of deficiencies. The most commonly cited systems deficiencies were among the most expensive components of the PACS.


Assuntos
Defesa Civil , Sistemas de Informação em Radiologia , Redes de Comunicação de Computadores , Sistemas de Gerenciamento de Base de Dados , Eficiência Organizacional , Órgãos Governamentais , Hospitais Militares , Humanos , Aprendizagem Baseada em Problemas , Serviço Hospitalar de Radiologia , Integração de Sistemas , Estados Unidos , Interface Usuário-Computador
13.
J Nutr ; 135(4): 761-4, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15795431

RESUMO

Starved male weanling rats supplemented with 20 mmol/L pivalate in their drinking water exhibit significantly depressed concentrations of carnitine in tissues and plasma. In addition, pivalate supplementation has been linked with increased renal and hepatic trimethyllysine hydroxylase (TMLH) activity, whereas carnitine supplementation has been associated with significantly decreased hepatic gamma-butyrobetaine hydroxylase (BBH) activity. The purpose of this study was to determine whether pivalate or carnitine supplementation affects the activity and genetic expression of 2 enzymes of carnitine (Cn) biosynthesis, TMLH and BBH, expressed as mRNA abundance, relative to the abundance of beta-actin mRNA. Male weanling rats were administered the control treatment (C; n = 6), the pivalate treatment (P; n = 7), or the pivalate treatment plus supplemental dietary carnitine (P+Cn; n = 7). Rats in group P had elevated renal TMLH activity, relative to the other groups (P < 0.05). The groups did not differ in the abundance of renal or hepatic TMLH or BBH mRNA. A previously unreported finding was the quantifiable level of renal BBH mRNA, which was verified by direct sequencing of the BBH cDNA product amplified from kidney RNA. The groups did not differ in renal BBH mRNA abundance and renal BBH enzyme activity was not detected. Thus, the alterations in enzyme activities in the pivalate-treated rats are not regulated at the transcriptional level, and are apparently related to post-transcriptional effects on the enzymes themselves.


Assuntos
Carnitina/deficiência , Carnitina/farmacologia , Regulação da Expressão Gênica/fisiologia , Lisina/análogos & derivados , Oxigenases de Função Mista/genética , Ácidos Pentanoicos/farmacologia , Animais , Carnitina/administração & dosagem , Carnitina/metabolismo , Suplementos Nutricionais , Rim/enzimologia , Fígado/enzimologia , Lisina/sangue , Lisina/metabolismo , Masculino , Oxigenases de Função Mista/metabolismo , RNA Mensageiro/genética , Ratos , gama-Butirobetaína Dioxigenase
14.
Am Surg ; 69(5): 387-91; discussion 391-2, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12769209

RESUMO

Approximately 80 per cent of patients with colorectal cancer have sporadic disease whereas the remaining 20 per cent seem to have a genetic component. Hereditary nonpolyposis colorectal cancer (HNPCC) is the most common autosomal dominant hereditary syndrome predisposing to colorectal cancer. Various methods have been described to screen for HNPCC and to directly test for mismatch repair gene mutations. This study evaluates the initial results of 1) microsatellite instability (MSI) and immunohistochemistry (IHC) staining of tumors and 2) genetic sequencing for mismatch repair gene mutations in patients suspected to have HNPCC. Appropriate patients for HNPCC testing were identified through a high-risk colorectal cancer clinic. Of those patients screened only those who met Amsterdam criteria (AC) for HNPCC or were young age onset (YAO) (<40 years of age) were eligible for testing. The tumors underwent testing for MSI and had IHC performed in those patients with available tumor specimens. MSI was performed on the five markers approved by the NIH consensus conference. MSI-High (MSI-H) was defined as two or more markers being unstable. IHC was done with commercially available stains for MLH1 and MSH2. All patients had sequencing of the MLH1 and MSH2 genes performed to search for mutations by a commercial laboratory. Genetic counseling was provided and written informed consent was obtained. Fourteen patients were part of kindreds that met the AC. An additional 10 patients were <40 years of age at diagnosis of colorectal cancer but lacked any family history. Testing for MSI and IHC was performed on those available tissue blocks. Of the AC patients five had MSH2 mutations and two had MLH1 variants. Of the five with MSH2 mutations three of four had MSI-H tumors and all four had loss of expression of MSH2 on IHC. Of the MLH1 variants only one had MSI-H tumor and lacked expression of MLH-1 on IHC. Of those patients with no mutation identified three of six had MSI-H tumors. For those patients YAO no genetic mutations were identified. Two of the seven had MSI-H tumors. Genetic testing for HNPCC even in those patients fulfilling the rigid AC yielded mutations in only five of 14 patients with variants of unknown significance being found in an additional two patients. Only one MSH2 variant of unknown significance was identified in the 10 YAO patients, which would suggest that screening in this group of patients with MSI and/or IHC would be appropriate.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas de Ligação a DNA , Testes Genéticos , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Pareamento Incorreto de Bases , Proteínas de Transporte , Análise Mutacional de DNA , Humanos , Imuno-Histoquímica , Repetições de Microssatélites , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS , Proteínas Nucleares
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